Companion bills setting federal standards for the welfare of egg-laying hens have been reintroduced in the U.S. Senate and House and have drawn immediate fire from San Francisco-based Humane Farming Association and more than 20 affiliated animal-protection groups.

"The egg industry wants to establish egg factory cages as a national standard that could never be challenged or changed by state law or public vote," Bradley Miller, national director of the HFA, said in a news release.

"The American public overwhelmingly supports the banning of egg factory cages, not measures such as this, which would ban the outlawing of cages. This bill would clearly subvert the will of the people," said Miller, who called the bill "outrageous."

The bills would codify an agreement between United Egg Producers, which has been sued for alleged price-fixing, and the Humane Society of the United States, which previously opposed the plan it now endorses, Miller said.

Schrader and Feinstein introduced similar bills in the last Congress to increase the size of hen cages but failed to gain enough support. Beside opposition from HFA and groups such as PETA that oppose any cages, the bills were strongly opposed by agricultural groups, which fear such legislation would set a precedent leading to national production and welfare standards for other livestock. Those groups include the American Farm Bureau Federation, National Cattlemen's Beef Association, National Pork Producers Council and other meat and dairy groups that remain opposed.

The bills require a phase-in of larger cages over 15 to 18 years at a cost United Egg Producers has estimated at $4 billion. State laws would be nullified and new state laws or ballot measures regulating egg production would be prohibited.

There are three minor changes in the 2013 bills, said Chris Huckleberry, legislative director for Schrader.

* A clause emphasizes the legislation pertains only to egg producers, not other livestock producers.

* Temporary exemptions to an ammonia limit of 25 parts per million in hen houses are allowed for emergencies such as extreme weather.

* Research facilities are added to farms of fewer than 3,000 laying hens as exempt from the bills.

Huckleberry said he anticipates some of the same struggles with some of the same opponents as last year.

"I think it's an uphill battle but we will continue to work this issue hard because we need to provide certainty for our egg producers," he said.

Greg Satrum, vice president of Willamette Egg Farms, Portland, has said Northwest egg producers need the federal bill to equalize state regulations to survive.

UEP spokesman Mitch Head has said UEP represents more than 90 percent of the nation's egg producers who say they need a federal bill to survive.

Half a dozen states have conflicting standards, which are becoming impossible for egg producers to navigate, he said.